Oxygen is the most abundant element on the earth's surface and as a gas is indispensable in respiration. Composing almost 21% of the atmosphere, oxygen is a colorless, odorless and tasteless gas which supports combustion. As a liquid at -297°F, oxygen is light blue in color and is approximately 14% heavier than water. Liquid oxygen is classified as a Type II by the Compressed Gas Association (CGA). CGA Pamphlet G-4.3, Type II, Grade B and the United States Pharmacopia (USP) specs are considered standards for commercial liquid oxygen.
